fix(web): re-read the viewed skill file on a skills/get fetch (#2516)

[cliffhall]

Closes #2516

Problem

The Skills screen read the selected skill's SKILL.md exactly once per manifest. The automatic read is guarded by autoReadKey === manifestKey, which exists so that StrictMode effect replays don't send a duplicate request. Fetch with skills/get sent only skills/get and compared the entry against the listing; it never re-read the file in the viewer. So if the server changed the file, the viewer kept showing the first resources/read response until the listing changed or the server was reconnected. That is the "stale response" in the report. No response cache was involved: core's readResource caches nothing, and ttlMs is not consulted on this path.

Fix

fetchEntry in SkillsScreen.tsx now also re-reads the file the viewer is showing, through the existing showResource path. That is SKILL.md by default, or the supporting file the reader opened. The re-read goes out right after skills/get, so the Protocol tab shows the two in the order the click implies. It reuses showResource's manifest key and attempt stamp, so a stale or superseded result is still dropped. It also keeps the rule that a re-read never overwrites a verification's own SKILL.md bytes.

Out of scope

The report lists three adjacent items. They are not part of this fix:

1. The Messages tab not showing a rejected skills/get response.
2. No way to call resources/directory/read. The Directory section already does this when the server declares directoryRead: true.
3. An error with no details after a successful fetch.

Tests

Two new cases in SkillsScreen.test.tsx:

• The fetch re-reads SKILL.md, and the viewer shows the server's new content.
• The fetch re-reads the supporting file the viewer is on, not SKILL.md.

npm run local:gate passes.

Screenshots

Captured at 1280×900 against test-servers/configs/skills-http.json. The fixture serves static content, so these show the traffic rather than changed content: after the click, a fresh resources/read follows skills/get.

Before clicking Fetch. One resources/read, from the selection:

After clicking Fetch with skills/get. skills/get, then a new resources/read of SKILL.md:

🤖 Generated with Claude Code

[Copilot]

🟢 Approval recommended

The refresh behavior is correctly attempt-stamped, preserves verification-owned content, and has focused regression coverage.

0 open findings

What changed in this PR

Refreshes the currently viewed skill resource whenever skills/get is fetched, preventing stale viewer content.

Changes:

• Re-reads the active SKILL.md or supporting file after skills/get.
• Adds tests for both viewer states.

File	Description
SkillsScreen.tsx	Refreshes the currently viewed resource on fetch.
SkillsScreen.test.tsx	Verifies entry and supporting-file refreshes.

🧠 Review effort: Balanced

---

💡 Add a code-review agent skill for context-aware, tailored reviews. Learn more in the docs.

[cliffhall]

Copilot review loop closed: round 1 was clean (0 open findings, no inline or suppressed comments), so no further round was requested.